This library offers integration with ViteJS to be used in ASP.NET applications. It's made to work mainly with MPA (Multi-Page Application).

The library is compatible with:

• MVC
• Razor Pages
• Blazor Server

This library has the following simple but very useful features:

• A Middleware to forward the requests to the Vite Development Server
• A service to access the Vite manifest.
• Tag Helpers for script and link tags.
• Start the Vite Development Server for you ❤️.

Install the package from NuGet.

dotnet add package Vite.AspNetCore

Add the following lines to your Program.cs or Startup class.

using Vite.AspNetCore;

// ---- Service Configuration ----
// Add Vite services.
builder.Services.AddViteServices();

// ---- App Configuration ----
// Use the Vite Development Server when the environment is Development.
if (app.Environment.IsDevelopment())
{
    // WebSockets support is required for HMR (hot module reload).
    // Uncomment the following line if your pipeline doesn't contain it.
    // app.UseWebSockets();
    // Enable all required features to use the Vite Development Server.
    // Pass true if you want to use the integrated middleware.
    app.UseViteDevelopmentServer(/* false */);
}

The common way to access Vite Development Server assets in your application is by using the following template, specifying the local URL where Vite Server is running.

<!-- Entry point for development -->
<environment include="Development">
    <script type="module" src="http://localhost:5173/@@vite/client"></script>
    <script type="module" src="http://localhost:5173/main.js"></script>
</environment>
<!-- Public assets -->
<environment exclude="Development">
    <img src="http://localhost:5173/assets/logo.svg" alt="Vite Logo" />
</environment>
<environment include="Production">
    <img src="~/assets/logo.svg" alt="Vite Logo" />
</environment>

Having to set up two ways to access public assets in different environments doesn't look very good. It can also be a problem in some circumstances. Service workers, for example, cannot be properly tested this way and if you are using preprocessors like SASS, you have probably noticed that your 'url()'s are not resolved correctly during development. But don't worry, this middleware will solve all those problems for you.

By using the vite middleware during development, you don't need to pass the development server URL. You can use aspnet paths as usual.

<!-- Entry point for development -->
<environment include="Development">
    <!-- It's mandatory to use the full url for the Vite client script. -->
    <script type="module" src="http://localhost:5173/@@vite/client"></script>
    <script type="module" src="~/main.js"></script>
</environment>

<!-- Public assets -->
<img src="~/assets/logo.svg" alt="Vite Logo" />

The middleware will proxy all requests to the Vite Development Server. You won't need alternative paths for images or other resources from your public assets. 🙀🙀🙀

To enable the middleware, pass true to the UseViteDevelopmentServer() method.

Note: The order of the middlewares is important! Put the UseViteDevelopmentServer(true) call in a position according to your needs. Otherwise, your assets will not be served as expected.

The Vite Manifest is a JSON file that contains the mapping between the original file names and the hashed names. This is useful to access the files in production environments.

By using the Vite Manifest service, you can access the manifest in your application by injecting the IViteManifest service. See the following example.

@inject IViteManifest Manifest

<environment include="Development">
    <!-- Vite development server script -->
    <script type="module" src="http://localhost:5173/@@vite/client"></script>
    <script type="module" src="~/main.ts"></script>
</environment>
<environment include="Production">
    <script type="module" src="~/@Manifest["main.ts"]!.File" asp-append-version="true"></script>
</environment>

You can also inject the manifest service in your controllers or services. See the following example.

public class HomeController : Controller
{
    private readonly IViteManifest _manifest;

    public HomeController(IViteManifest manifest)
    {
        _manifest = manifest;
    }

    public IActionResult Index()
    {
        var mainFile = _manifest["main.ts"]?.File;
        return View();
    }
}

Do you want to render your entrypoint scripts and styles in the simplest way possible? You can use the special tag helpers provided by this library. First, add the following line to your _ViewImports.cshtml file.

@addTagHelper *, Vite.AspNetCore

Now you can use the vite-src and vite-href attributes in your scripts and links. See the following example.

<!-- This line includes your styles entrypoints -->
<link rel="stylesheet" vite-href="~/main.ts" />

<!-- This line includes your "main.ts" and "secondary.ts" entrypoints -->
<script type="module" vite-src="~/main.ts" asp-append-version="true"></script>
<script type="module" vite-src="~/secondary.ts"></script>

This tag helpers will do the following magic according the state of the Vite Development Server (VDS).

• VDS is enabled:
  • If the link tag is a script (you want to include css from a script entrypoint), the link tag will just disappear. This is because Vite loads the styles automatically by including the script.
  • If the script of the Vite client is not included, it will be added automatically.
• VDS is disabled:
  • The link and script tags will be rendered using the original paths taken from the manifest. The value of the vite-href and vite-src attributes will be used as the entrypoint to access the manifest.

The rendered HTML when the VDS is enabled will look like this.

<!-- This line includes your styles entrypoints -->

<!-- This line includes your "main.ts" and "secondary.ts" entrypoints -->
<script type="module" src="http://localhost:5173/@vite/client"></script>
<script type="module" src="http://localhost:5173/main.ts"></script>
<script type="module" src="http://localhost:5173/secondary.ts"></script>

And the rendered HTML when the VDS is disabled will look like this.

<!-- This line includes your styles entrypoints -->
<link rel="stylesheet" href="/css/main.css" />

<!-- This line includes your "main.ts" and "secondary.ts" entrypoints -->
<script type="module" src="/js/main.js?v=bosLkDB4bJV3qdsFksYZdubiZvMYj_vuJXBs3vz-nc0"></script>
<script type="module" src="/js/secondary.js"></script>

Note: The final paths and filenames depend on how you set it in your vite.config.ts file.

The services can be configured by passing options to the AddViteServices() function, using environment variables, user secrets, or your appsettings.json file.

Passing the options to the AddViteServices() function is as simple as you can see in the following example:

// Program.cs
using Vite.AspNetCore;

// ...
// Add the Vite services.
builder.Services.AddViteServices(options =>
{
    // By default, the manifest file name is ".vite/manifest.json". If your manifest file has a different name, you can change it here.
    options.Manifest = "my-manifest.json",
    // More options...
});
/// ...

If you prefer not to hardcode the options, you can use environment variables or user secrets. I suggest using appsettings.json and/or appsettings.Development.json files to share the default configuration with other developers. This information is not sensitive, so it's safe to share it.

// appsettings.json
{
    "Vite": {
        "Manifest": "my-manifest.json"
    }
}

// appsettings.Development.json
{
    "Vite": {
        "Server": {
            // Enable the automatic start of the Vite Development Server. The default value is false.
            "AutoRun": true,
            // The port where the Vite Development Server will be running. The default value is 5173.
            "Port": 5174,
            // Pass true, if you are using HTTPS to connect to the Vite Development Server. The default value is false.
            "Https": false,
        }
    }
}

In the previous example, i used the appsettings.json and appsettings.Development.json files to keep the configurations for each environment separated. But you can use only one file if you prefer.

Config mechanisms are exclusive to each other and can't be mixed. Service configuration has priority load over Environment Variable configuration.

There are more options that you can change. All the available options are listed below. ⚙️

If you are using the appsettings.json and/or appsettings.Development.json files, all the options must be under the Vite property.

Do you want to see how to use this library in a real project? Take a look at these examples